Fermilab's finding may cause problems for CERN. Credit: FERMILAB

Physicists have placed fresh limits on the mass of the Higgs boson — the particle thought to confer mass on other matter.

The particle was assumed to have an energy (or equivalent mass) of between 114 and 185 gigaelectronvolts (GeV). But, after analysing pooled data, researchers at the Tevatron particle accelerator at the Fermi National Accelerator Laboratory in Batavia, Illinois, announced on 13 March that the particle can be excluded at energies of between 160 and 170 GeV, and is likely to exist at the lower end of the assumed range.

At more-crowded lower energies, filtering out other debris and finding a rare Higgs event becomes more difficult. Scientists at the Large Hadron Collider at CERN, Europe's particle-physics laboratory near Geneva, had hoped to find the Higgs boson in the higher-energy region.